The two box designs here can be found in
several websites related to barn owls. They are collected here
for convenience. As well, several sites with other barn owl nest
box plans are listed below.

The box design shown below has been across the
United States for many years. While being somewhat on the snug
side, it is readily accepted by owls. This box may be easily
attached to a pole or the side of a building.

The arrangment show below illustrates how a
nest box can be hung in the interior of a building with outside
access for the birds. This is approach is particulary useful if
the presence of the owls is not wanted inside the barn.

Don't like either of these? Check out the Barn
Owl nest box plans on About.com's How To Build Birdhouses , a
very comprehensive guide to building nest boxes for many avian
species.

Another good set of plans for a simple, but
effective, box can be found at Make a Barn Owl Nest Box. This
site is published by the Missouri Department of Conservation.

Nesting Box Plans from the
North Carolina Extension Service has dimensions and a cut-out
plan for a nest box design that should attract barn ,screech and
barred owls.

Don't forget to take a look at Bio-Diversity's
Construction Guides for both barn owls
and kestrels. Okay, so they cost a couple of bucks, but they are
very complete. You get suggestions for location, parts lists,
equipment needed, cutting plans and step by step instructions.
Now that has to be worth something, doesn't it?